PORT ST. LUCIE, Fla. — Steven Matz says he is throwing pain-free after recovering from surgery in August to reposition the irritated ulnar nerve in his left elbow.

Barring a trade, the only lefthanded starter with a chance to break up the Mets’ otherwise all-righthanded rotation is the 26-year-old Stony Brook native.

“I feel really good coming into camp, so I’m excited,” Matz said Friday morning after workouts, including a 25-pitch bullpen session in 79-degree sunshine at First Data Field. “This was my fifth bullpen of the year, so I’m doing really good mentally.”

Matz said he resumed throwing in early December.

Though Matz had a shoulder injury in 2016, problems with his left elbow have marred his career since the Mets made him their second-round pick in 2009 out of Ward Melville High School in East Setauket.

Shortly after being drafted, Matz had Tommy John surgery on that elbow, so he did not make his professional debut in the rookie-level Appalachian League until June 2012.

Matz rose quickly through the minors, though, and made his major-league debut in June 2015 with a win over Cincinnati in which he also had three hits and four RBIs, an MLB record for a pitcher in his first game.

After his second start, he tore a latissimus dorsi muscle and missed a month, though he pitched well in September and three postseason starts.

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The following season, surgery to remove a bone spur in Matz’s pitching elbow cut his season short after 22 starts.

Last season, elbow inflammation delayed his first start with the Mets until June 10.

After pitching seven shutout innings at Washington on July 2, Matz was 2-1 with a 2.12 ERA after five starts, but he went 0-6 with a 10.19 ERA in his next eight starts before having the surgery to move the ulnar nerve.

Seeing the rest of the Mets’ projected rotation coming to camp healthy, and former pitcher Mickey Callaway as their new manager, gives Matz renewed hope.

“I think they’re great,” he said of Callaway and new pitching coach Dave Eiland. “They seem real organized, and they seem real fired up and really confident that they’re going to win with this team.”

Matz got married during the offseason, which also might have helped his mental outlook.

“It was one of the best days of my life,” he said. “It’s been great.”

The only lefty reliever on the Mets’ roster, Jerry Blevins, an 11-year veteran entering his fifth season with the Mets, likewise is eager to start working with Callaway and Eiland.

“Any former pitchers I’m always trying to learn from, so having him [Callaway] at the helm can’t be anything but beneficial for me,” Blevins said.

The only other lefty pitchers coming to camp, which officially opens for pitchers and catchers on Monday, are P.J. Conlon, 24, who started 22 games last year for Double-A Binghamton, and Matt Purke, 27, who made one start among 86 appearances during the past two seasons with the White Sox and their Triple-A affiliate.